/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 *    PropertyNode.java
 *    Copyright (C) 1999 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.experiment;

import weka.core.RevisionHandler;
import weka.core.RevisionUtils;

import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.io.IOException;
import java.io.Serializable;

/**
 * Stores information on a property of an object: the class of the object with
 * the property; the property descriptor, and the current value.
 * 
 * @author Len Trigg (trigg@cs.waikato.ac.nz)
 * @version $Revision: 1.7 $
 */
public class PropertyNode implements Serializable, RevisionHandler {

	/** for serialization */
	private static final long serialVersionUID = -8718165742572631384L;

	/** The current property value */
	public Object value;

	/** The class of the object with this property */
	public Class parentClass;

	/** Other info about the property */
	public PropertyDescriptor property;

	/**
	 * Creates a mostly empty property.
	 * 
	 * @param pValue
	 *            a property value.
	 */
	public PropertyNode(Object pValue) {

		this(pValue, null, null);
	}

	/**
	 * Creates a fully specified property node.
	 * 
	 * @param pValue
	 *            the current property value.
	 * @param prop
	 *            the PropertyDescriptor.
	 * @param pClass
	 *            the Class of the object with this property.
	 */
	public PropertyNode(Object pValue, PropertyDescriptor prop, Class pClass) {

		value = pValue;
		property = prop;
		parentClass = pClass;
	}

	/**
	 * Returns a string description of this property.
	 * 
	 * @return a value of type 'String'
	 */
	public String toString() {

		if (property == null) {
			return "Available properties";
		}
		return property.getDisplayName();
	}

	/*
	 * Handle serialization ourselves since PropertyDescriptor isn't
	 * serializable
	 */
	private void writeObject(java.io.ObjectOutputStream out) throws IOException {

		try {
			out.writeObject(value);
		} catch (Exception ex) {
			throw new IOException("Can't serialize object: " + ex.getMessage());
		}
		out.writeObject(parentClass);
		out.writeObject(property.getDisplayName());
		out.writeObject(property.getReadMethod().getName());
		out.writeObject(property.getWriteMethod().getName());
	}

	private void readObject(java.io.ObjectInputStream in) throws IOException,
			ClassNotFoundException {

		value = in.readObject();
		parentClass = (Class) in.readObject();
		String name = (String) in.readObject();
		String getter = (String) in.readObject();
		String setter = (String) in.readObject();
		/*
		 * System.err.println("Loading property descriptor:\n" +
		 * "\tparentClass: " + parentClass.getName() + "\tname: " + name +
		 * "\tgetter: " + getter + "\tsetter: " + setter);
		 */
		try {
			property = new PropertyDescriptor(name, parentClass, getter, setter);
		} catch (IntrospectionException ex) {
			throw new ClassNotFoundException(
					"Couldn't create property descriptor: "
							+ parentClass.getName() + "::" + name);
		}
	}

	/**
	 * Returns the revision string.
	 * 
	 * @return the revision
	 */
	public String getRevision() {
		return RevisionUtils.extract("$Revision: 1.7 $");
	}
} // PropertyNode
